ELMERS Carpenter's Wood Filler 1/2-Pint (E848D12)

I would put a nice layer of wood filler over the fins (except for the tab) and body tube, then sand it down using 220. Once that's smooth, attach the fins to the tube. Use more wood filler as needed, and when ready, paint with a high build primer(note, it's not a miracle worker, you need a pretty smooth surface to start with). Sand the primer down with 400 grit, add more wood filler as needed. Once it's smooth, put on a coat of white, lightly wet sand, then apply to final color coat. Make sure you have 1-2 days between layers of paint, otherwise it's hard to sand and doesn't adhere properly.